Precision torque release and part marking wrench



Aug. ll, 1970 I c. J. LANCE 3.523,471

PRECISION rvPORQUE! RELEASE AND PART MARKING WRENCH Filed Nov. 8, 1967 2Sheets-Sheet l CHRlSTOPHER JAMES LANCE ATTORNEY S c. J. LANCE Aug. 11,15W() A PRCISION 'PORQUE RELEASE AND PART MARKING 'WRENCH Filed Nov. 8,1967 2 Sheets-Sheet 2 l NVENTOR CHRISTOPHER JAMES LANCE bm mm www mmATTORNEYS United States Patent O 3,523,471 PRECISION TORQUE RELEASE ANDPART MARKING WRENCH Christopher James Lance, Royal Oak, Mich., assignerof fifty percent to Ivan F. Belknap, Den-oit, Mich. Filed Nov. 8, 1967,Ser. No. 681,423

ABSTRACT OF THE DISCLOSURE A high precision-type torque release ortorque limiting wrench is disclosed which has extremely simpleprovisions to mark a threaded part which is tightened by the wrench atthe instant that the exact intended maximum torque has been applied tothe part, and precisely simultaneously with the cessation of applicationof torque to the part.

As a wrench, per se and without reference to its uniquely associatedmarking means, the tool shown herein is of a generally conventionaltype. However, its builtin marking structure is, pursuant to theimprovement, directly associated with an operated by a pivotal torqueapplying arm of the wrench, which arm conventionally carries atorque-applying head engageable through a socket-type chuck or like sortof driver with the threaded part to be taken up.

The marking means may be of a pneumatically actuated type, in whichpower to effect an instantaneous marking of the part, at a desiredtorque break limit designed into the wrench, derives through anappropriate valve connected between an air pressure source and a plungerunit which applied the mark. Equivalent iluid pressure drivers arecontemplated.

In the alternative, the control may be an electric solenoid type,including a suitable switch through which a solenoid coil is energizedat the instant the critical break torque is reached, thereby operating,in the manner of an armature, a plunger type device of one sort oranother which applies the mark. Other alternative controls arecontemplated which are equivalent to the pneumatic and electricalversions.

In any of the possible alternative forms, it is of the essence of theinvention that the control provisions, fluid pressure, electrical ormechanical, be in turn responsive directly to the shift of a torqueapplying arm (or other member constituting a part of the wrench andmovable at the instant the intended torque break limit is reached), witha corresponding instantaneous and direct application of motivating powerto the marking component of the wrench.

BACKGROUND OF THE INVENTION Field of the invention The wrench findsapplication in many settings, as in automotive, aircraft and relatedproduction lines, mass production or otherwise, in which a veryimportant consideration is than an identically equal maximum designedtorque be applied to each of a number of threaded fasteners (bolts,nuts, screws and the like) of any given assembly or a number thereof incourse of handling. The desire and intent is that there shall be noperceptible variations at all in the torque to which the fastener partis finally taken up. It follows that possibly unequal localized anddangerous stressing of secured and securing parts is safely avoided.

More particularly, in the use of torque limiting wrenches in massproduction or assembly it is highly desirable that an inspector, withoutmaking individual manual wrench-check-ups of each of a possibly largenumber of CTI Mice

Description of the prior art The patents to R. G. Woods No. 2,274,638 ofMay 1,

1956, No. 2,897,704 of Aug. 4, 1959 and No. 3,016,773 of Ian. 16, 1962,all show torque limiting or release wrenches of the general typeinvolved in the present tool, but llacking marking means of any sortsuch as is an important factor in the combination which is herein shownand claimed.

The patent to Hines et al. No. 3,009,371 of Nov. 21, 1961, deals withpart marking means incorporated in a torque release wrench, but theseprovisions are of a highly complex and expensive nature, as comparedwith the simplicity, compactness and low production cost of the directaction marker means of the invention, all coupled with precision ofresponse to de-torsioning.

SUMMARY yOF THE INVENTION The invention resides in a combined torquelimiting and part marking wrench which is basically constituted by avery few, extremely simple yet reliable operating components. These, inthe general manner of Woods 2,743,638 and 3,016,773, identified above,comprise an elongated tubular handle having a torque transmitting armpivotally mounted therein, with a torque applying head rigidly connectedto an outer end of the arm; a plunger slidably mounted within the handleadjacent an opposite end of the latter and biased toward the torque armby adjustable spring means; and a simple pivot dcvice operativelyinterconnecting the plunger with the adjacent end of the arm. Typically,this is clfectuated in such manner that the torque arm shifts when thevalue of the torque exerted on a threaded part (representing a load)engaged by the -wrench head reaches a value sufficient to overcome theplunger-applied spring force acting through the pivot device on thetorque applying arm. The line of torque transmission to the head breaks,signaling to the operator that the desired maximum torque has beenreached and further elort should end.

Directly associated with this type of wrench, as at its tubular handleand at its torque applying head, the invention contemplates a unit bywhich a mark of one sort or another is applied to the threaded partexactly simultaneously with the interruption of torque transmission.This unit includes a member directly engaged and operated by the shiftedtorque arm, or some other member shiftable in the Wrench, rather than inresponse to an involved and expensive operating line of parts. The unitmay include a valve controlling the application of uidpressure operatingforce to a marker-carrying plunger, or the control may comprise a simpleelectrical onoff switch similarly actuated by the torque transmittingarm or equivalent member of the tool and governing the drive of themarker, as through a solenoid.

The nature of the marker and the particular mark applied to the part mayof course also vary. Thus, the marker may be a plunger driven punchacting to locally deform and permanently identify the part visually asbeing acceptable. Alternatively, the marker may be a ballpoint andcartridge type of paint or ink applicator.

In the case of an electrically acting actuator unit, it may be poweredfrom an appropriate line source, usually through transformer means, orby any of a number of available types of battery sources. A strictlymechanical line of direct action from the wrench to its marker is alsocontemplated.

BRIEF` DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view, partiallybroken away and in longitudinal horizontal, and in the main axial,crosssection, illustrating an embodiment of the wrench of the inventionin which the intended mark is applied to the tightened bolt or like partthrough the agency of valvecontrolled pneumatic or other uid pressurepowered means, this embodiment being one in which the part ispermanently marked by deformation;

FIG. 2 is a fragmentary view of the wrench of FIG. l in side elevation,being partially broken away andin vertical section on line 2 2 of FIG.1;

FIG. 3 is a fragmentary side elevation of a modified adaptation of the-wrench of FIGS. l and 2, in which the mark is applied by a ballpointpen type of cartridge unit, this embodiment also optionallyincorporating a horizontally acting actuator unit for the marker whichmay, as in the wrench of FIGS. 1 and 2, be tiuid pressure-powered:however, electrical solenoid operation is also contemplated;

FIG. 4 is a top plan view, partially broken away and in horizontalsection, as in FIG. 1, illustrating a further modified embodimentemploying an electrically powered and controlled solenoid type ofmarking unit, plus additional electrical connections to a recordingdevice (if this be deemed desirable), this wrench being further equippedto handle both right and left hand threaded parts;

FIG. 5 is a fragmentary view in vertical cross-section on broken line5-5 of FIG. 4;

FIG. 6 is a fragmentary schematic view in side elevation and somewhatlesser scale of a wrench similar to that of FIGS. 4 and 5, partiallybroken away and in vertical cross-section but utilizing a paint or inkcartridge unit as the marker; and v FIG. 7 is a more or less schematictop plan view of a still further modified wrench embodying battery meansas the source of marking power.

DESCRIPTION OF PREFERRED EMBODIMENTS Reference being had to FIGS. 1 and2, the embodiment 10 of the precision torque release and marking wrenchshown therein is generally similar in its torque limiting aspect to the-wrench of Woods 2,743,638: this is true both in regard to its mainstructural features and the operation thereof in taking up a threadedpart, such as the bolt B appearing FIG. 2 hereof. Accordingly, thesefeatures and their operation need but brief description.

Wrench 10 comprises an elongated tubular, housinglike operating handle12 of cylindrical cross-section which slidably receives a cylindricalplunger 14. A coil compression spring 15 acts against plunger 14 tooppose movement of the latter to the left, as viewed in FIG. 1. Spring15 is backed by an abutment disk 16, which is in turn sustainedrearwardly by an adjustable screw 17 threaded axially in an end portion18 of handle 12.

A11 elongated torque transmitting arm 20 is pivotally mounted on atransverse axis within handle 12, as by a pin 21 adjacent the forward orright-hand end of the latter, as viewed in FIG. 1; and a small floatingtype pivot member 22 is disposed between the left-hand end of arm andthe right-hand end of the spring-sustained torque plunger 14. The pivot22 acts sensitively in the fashion described in Woods 2,743,638 when arm20 shifts pivotally under a critical break torque of a maximum designedvalue, the member 22 rocking laterally and causing plunger 14 to yieldto the left and arm 20 to swing laterally. This is of course accompaniedby the break of the line of torque transmission to bolt B, in the usualmanner.

Specific structural aspects of the pivot 22 constitute no part of thepresent invention, and the use of any equivalent type of responsivecoupling or coupling member is contemplated. Furthermore, thearrangement may be such as to permit the drive of bolt B only inresponse to clockwise swing of the lwrench, as viewed in FIG. l, or itmay be such as to respond to both clockwise and counter-clockwise swingof handle 12, as illustrated and described in the last-mentioned patent.This is the case in the embodiment of FIGS. 4 and 5 hereof wherein thepart B may be marked regardless of the direction of its threading.

Torque transmitting arm 20' carries, externally of tubular handle 12 andto the right (FIG. 1) of its pivotal axis at pin 21, the usual torsionhead, generally designated 24. This head will usually be of a pawl andratchet type familiar to` the industry. A pneumatic cylinder unit,generally designated by the reference numeral 26, is applied to head 24,being serviced by a control valve unit 28 operatively connected theretoand mounted on the tubular handle of wrench 10.

The wrench is shown as operating a tubular socket 29 mated over thehex-head of bolt B, this socket having a square axial opening 30 at itstop upwardly mating a male formation 31 of the same cross-section whichis integral with the bottom of a generally T-sectioned operator '32.This operator is pawl and ratchet-engaged, in a known manner and bymeans not shown, by the torque head 24 of wrench 10, with an appropriatebottom washer 33 fixed on head 24 sustaining operator 32 from beneath.The latter is cylindrical at its main body portion where torque isreceived, being conventionally received in a cylindrical counterbore 34of head 24. Thus, indexing movement of handle 12 in a clockwisedirection (FIG. 1) transmits clockwise torque through operator 32 andsocket 29 to bolt B. As indicated above, head 24 may posses knownrefinements, for example as are shown in Woods 2,897,704, to transmitthe torque both clockwise and counterclockwise. These featuresconstitute no part of the present invention.

The pneumatic cylinder unit 26 includes a radially outwardly flangedbase member or plate 36 (FIG. 2) having a cylindrical, reduced diameterbottom extension 37 which pilots in a cylindrical top recess orcounterbore 37 in operator 32. Screws 3-8 secure the base 36 of unit 26to head 24, said unit indexing with the head in the ratcheting action ofthe wrench. An upright pressure cylinder 39 is seated in a top recess inbase member 36, the cylinder being capped by a top plate 40 into whichthe upper end of the cylinder is recessed; `and the three cylinder andplate parts 36, 39 and 40y are rigidly held in assembly by verticallyelongated studs 41.

Cylinder 39 receives a cylindrical plunger head 42 on the top of anelongated rod 43 which is slidably received in aligned bores 44 and -45of the cylinder base 36 and the operator 32, respectively; and a coilcompression spring 46 is disposed between plunger head 42 and basemember 36.

Downwardly of the operator extension 31, and normally within the confineof the torque-applying socket 29, the plunger rod 43 is equipped, in theembodiment of FIGS. 1 and 2, with a suitable punch `47 having apart-indenting tip 48 at its bottom, the action of which is, uponpressurization of the cylinder 39', to provide a permanent visualindicium that the bolt B, or other part operated upon, has been taken upto an exact desired extent. The punch 47 of the embodiment of FIGS. land 2 may, if desired, be replaced by some other type of marker leavinga less permanent signal.

As illustrated in FIGS. 1 and 2, cylinder unit 26= is pneumaticallypressurized at the instant of reaching the break value of torque, withresultant swing of wrench arm 20, through a flexible pressure line ortube 50, which is attached to unit 26 by means of a suitable fitting 51threaded in an opening in cylinder plate 40. The tube 50* is similarlyconnected through an L-tting 52 toan opening in the side of a housing 53of the valve unit 28; the housing being suitably mounted directly to theside of the tubular wrench handle 12, as by means of a threaded iitting54 (FIG. 1) received in an opening in the handle at a substantialdistance rearwardly, or to the left, of the pin 21 pivoting arm 20` tothe handle.

Valve 28 is a simple On-Ot`r' type, being equipped with a llexiblepressure tube or line I55 connecting it to a source of pneumaticpressure (not shown); and an operating element or button 56 of valveunit 28 is exposed within the tubular handle at a point relativelyclosely adjacent the torque arm 20 in a neutral, non-shifted position ofthat arm.

The operation of the kwrench embodiment is believed evident from theforegoing description. Upon the torque reaching the break value when thewrench is manipulated clockwise as viewed in FIG. 1, arm 20 swingsinstantaneously counterclockwise about its pivotal axis 21, interruptingthe line of torque transmission to socket 29 and simultaneouslydepressing the operating button -56 of valve 28. The latterinstantaneously pres surizes tube 50 and cylinder unit 26 from thepressure source, with the result that the punch 47 (or equivalentmarking device on plunger rod 43) is driven in opposition to spring 46to place the desired mark on the part B.

FIG. 3 illustrates a modi-lied embodiment of the principle of theinvention, the marker of which may be considered to be a pneumaticallyoperated one, although hydraulic, electrical or mechanical control arealso contemplated. Here a cylinder unit 58 is appropriately mounted uponthe top of the handle 12 of the wrench, which is generally designated'by the reference` numeral 60; and an elongated operating stem 61projects axially and horizontally from the end of the cylinder 58. Uponpressurization or equivalent powering of the latter, stem 61 is drivento the right, as viewed in FIG. 3, which action may be in opposition tosuitable internal spring means of the cylinder, as in the embodiment ofFIGS. 1 and 2.

The torque applying head 24 of tool 60 slidably receives (in the mannerof the arrangement of FIG. 2) a vertically elongated plunger rod 62,which rod terminates above the head 24 in an enlarged tappet 63. Rod 62should be urged upwardly to a predeterminedly limited elevation, as byspring means 64, and when the operating stem 61 is driven to the right(FIG. 3) it engages the top of tappet 63 in the manner of a cam or wedgeto drive plunger rod 62 downwardly. The latter is shown in this instanceas being equipped with a cartridge device 65 to place the desired markin paint, ink, cement, or glue on the bolt or like part B. Indentationof the latter by a punch is also contemplated. In addition it should beappreciated that the marking device may contain a threaded sealer, suchas the type sold under the trademark Loc-Tite, which is engageable withthe threaded nut and which seals the threaded fastener extending throughthe nut after the nut is torqued as required.

FIGS. 4 and 5 illustrate one version of a bidirectionally indexableprecision torque wrench and solenoid-operated marker assembly, generallydesignated [by the reference numeral 66. Inasmuch as the basic operatingstructure of this wrench may well be, and is shown as, identical to thatof the embodiment of FIGS. 1 and 2, corresponding features have beendesignated by corresponding reference numerals, primed, and furtherdescription thereof is dispensed with Wrench 66 has an electricallyenergizable solenoid unit fixedly secured atop torque applying head 24',which will include an appropriate reversible pawl and ratchet drivedevice (not shown) of known sort between the head and the operator 32.The connection of unit 67 is shown as being effected at a flanged base68 of the unit, using screws 69 threaded into the top of head 24'.v

Base 68 has a central bore 70 coaxially aligned above the topcounterbore 37 in the operator 32'; and an alongated plunger rod 72 isslidably received in the central bore 45 of operator extension 31'.

The upper end of rod 72 extends into operator counterbore 37 and basebore 70, terminating just beneath the lower end of an armature plunger75 of solenoid unit 67. This plunger member is slidable in the annularflanged spool or core 76 on which a solenoid coil 77 is Wound, thearmature member 75 having 'an integral enlarged head 78 to limit itsdownward stroke. Solenoid unit 67 is preferably encased and shielded byan inverted housing 79 suitably aixed to the top of torque applying head24'; and terminals of coil 77 receive electric leads -80 and 81, whichare brought out of the housing, preferably through suitable grommetmeans of a known type (not shown).

As shown in FIGS. 4 and 5, the electrical circuitry of the wrench 66includes a small, normally open push ibutton type microswitch 82suitably mounted on a side of the tubular handle 12 of the tool andencased and shielded by a housing 83. A push button element 84 of switch82 projects through an opening 85 in handle 12 into position foroperation to close the contacts of switch 82 when the break value oftorque is reached and arm 20 swings counterclockwise (as viewed in FIG.4) about its pivotal axis at 21. Wiring lead 80 is connected to oneterminal of the switch; lead 81 is connected to an appropriate electricpower source (not shown), for example a step-down transformer; and athird lead 86 is connected to a second terminal of switch 82, thuscompleting this particular solenoid circuit.

Upon closure of switch 82, solenoid unit 67 is energized, thus drivingits armature plunger 75 down onto marker rod 72 and, through the agencyof the punch 87 on the latter, applying the desired acceptance indiciumto the top of bolt B. As before, a non-indented type of mark may beapplied.

In certain installations it may be desirable to effect a permanentrecord of the number of checks for torquecorrectness that have ben madefor any given structure under assembly or the like. To this end, thewiring leads 80, r81 of wrench 66 are connected by wires 83, 84,respectively, to a suitable and known type of recording device 86, asshown in FIG. 4, so that each electrical impulse energizing the solenoidunit 67 correspondingly energizes device 86 to make a permanent record,which should reflect a check on each and every one of a possibly largenumber of threaded fasteners B of an assembly.

As indicated above, the wrench embodiment 66 is one in which bothclockwise and counterclockwise swings of its torque arm 20 may takeplace, for example, in operating on right and left-hand threadedfasteners. In such a unit, the switch means 82 and associated wiring areduplicated at the opposite side of tubular handle 12', withcorresponding conections to solenoid coil 77 and to the recorder 86, ifone is utilized. In the interest of simplicity, such switch and wiringmeans are designated in FIG. 4 by reference numerals which correspond tothose set forth above, but are primed.

FIG. 6 of the drawings illustrates an embodiment 92 of the wrench of theinvention which is in the main similar to that just described, so thatcorresponding reference numerals are employed to designate correspondingparts. In this form the marking device is shown as being a ballpoint penand cartridge unit 93 carried by a plunger 94, this plunger 'beingoperated through the solenoid unit 67 in the same manner as the punch 87of the embodiment of FIGS. 4 and 5.

Assuming that the tools 66 and 92 are operated under switch control froma power line, possibly involving ap propriate transformer provisions,the improvement of the invention also contemplates an embodiment, suchas generally designated 96 in FIG. 7, whose electrical energy source isbuilt in. Thus, one or more simple batteries may constitute a batterypower unit 97 ixedly secured to the tubular handle 12' of the tool 96.Such batteries are widely and inexpensively available, for example of arechargeable nickel-cadmium type, or of the phototlash, alkaline orashlight types. One terminal of battery unit 97 is connected by a lead98 to a terminal of switch 82, the second terminals of the battery unit97 and the switch being electrically connected to the solenoid unit 67by the respective leads 80 and 81.

While the invention has been illustrated and described as embodied in awrench having a torque-applying head at one end of a torque-sensing arm,it is to be understood that the principle of the invention may well alsoind ap- .plication in other related tools, such as, for example, aSpanner wrench.

What is claimed is:

1. A combined type of torque applying, limiting and marking wrench,comprising means to apply a given, predeterminedly limited torquingforce to an object and terminate said application when the force limitis reached, including an elongated tubular operating member having anelongated, rigid but yieldably-acting torque arm swingable therein aboutan axis transverse of its length, said arm being means to drivinglyconnect it to said object, means controlling termination of theapplication of force by said first named means; and a unit responsive todirect engagement by said arm to apply a mark to said objectsimultaneously with the termination of application of said force, saidunit including an element mounted by said tubular member and directlyengaged by said torque arm 'upon said termination.

2. The wrench of claim 1, in which said means drivingly connecting saidtorque arm to the object includes a rotatable torque applying head onsaid arm, said head having means to drivingly connect it to the object,at least a part of said marking unit being mounted on said head.

3. The tool of claim 1, in which said unit is a fluid pressure operatedone.

4. The tool of claim 1, in which said unit is an electrically operatedone.

5. The wrench of claim 2, in which said unit is a fluid pressureoperated one.

6. The wrench of claim 2, in which said unit is an electrically operatedone.

7. A combined type of torque applying, limiting and marking wrench,comprising means to apply a given, predeterminedly limited torquingforce to an object and terminate said application when the force limitis reached, including a yieldably-acting, movable member having means todrivingly connect it to said object; and a unit responsive to directengagement by said member to apply a mark to said object simultaneouslywith the termination of application of said force, said yieldably-actingmember being a torque arm, said unit comprising a control elementdirectly contacted and operated by said torque arm when the limit isreached, and an operating connection between said control element andanother part of said marking unit to activate the latter to apply saidmark, said torque arm being internally housed by said first-named means,said operating connection between said control element and said part ofthe marking unit being substantially instantaneously responsive to saidtermination of application of the torquing force, said means drivinglyconnecting said torque arm to the object including a rotatable torqueapplying head on an end of said arm, said head having means to drivinglyconnect it to the object, at least a part of said marking unit beingmounted on said head, said unit being a fluid pressure operated one inwhich said head-mounted part of the marking unit comprises a liuidpressure-operated cylinder, said marking unit further comprising acontrol valve mounted on said arm-housing means and having tubularpressure-transmitting means communicating the valve with said cylinder.

8. The wrench of claim 6, in which said head-mounted part of the markingunit comprises a solenoid, said element of said marking unit being aswitch mounted on said tubular member and having wiring meanselectrically connecting the switch with said solenoid.

9. The wrench of claim 7, in which said pressure-transmitting means isexible to permit rotation of said cylinder with said head.

10. The wrench of claim 8, in which said wiring means is flexible topermit rotation of said solenoid with said head.

11. The tool of claim 1, in which said unit has means visuallyidentifying the object by deforming the latter.

12. The tool of claim 1, in which said unit has means visuallyidentifying the object by applying paint or ink to the latter.

13. The wrench of claim 2, in which said marking unit has means markingthe part by deforming the latter.

14. The wrench of claim 7, in which said marking unit hasmeans markingthe part of deforming the latter.

15. The wrench of claim 8, in which said marking unit has means markingthe part by deforming the latter.

16. The wrench of claim 2, in which said marking unit has means markingthe part by applying paint or ink to the latter.

17. The wrench of claim 7, in which said marking unit has means markingthe part by applying paint or ink t0 the latter.

18. The wrench of claim 8, in which said marking unit has means markingthe part by applying paint or ink to the latter.

References Cited UNITED STATES PATENTS 1,131,225 3/1915 Farkell 8l-52.31,748,218 2/1930 Groves 81-53 1,985,916 1/1935 Coates et al. 8l-52.52,756,622 7/1956 La Belle 81-52.4 2,897,704 8/1959 Woods 81-52.42,901,934 9/1959 Dunham 81-53 2,996,940 8/1961 Van Hoose 81-52.43,009,371 11/1961 Hines et al 81-53 3,060,763 10/1962 Neufeld et al81-52.4 X 3,202,021 8/ 1965 Livermont 81-52.4 3,389,623 6/1968 Gill8l-52.3

JAMES L. JONES, IR., Primary Examiner U,S. C1. X.R. 7 3-139

